Polygamy has hurt the wellbeing of a polygamist's child(ren).
Children grow up to be more stable, hardworking and compassionate people when in a kind environment, with the active comfort of their parents and family. Yet, the child(ren) would be put in a worse position, in which his/her father would pay more attention to his wives than to him/her. Research suggests that children in polygynous families do worse educationally and psychologically than their peers in monogamous families.
Evidence suggests that the jealousy of the other not bearing the child(ren) would lead to domestic violence, leaving the child emotionally insecure and create a concept known as "The Cycle of Violence," where someone has been exposed to violence for a great amount of time, later influencing him/her to be violent towards someone who will later be violent towards others.

So, let me establish that there are two "types" of polygamous marriage.

Type One: a marriage that produces offspring
Type Two: a marriage that does not produce offspring

You have addressed Type One, while failing to address Type Two. You claim that the child/children of polygamous marriages would be "put in a worse position." You claim that the father would "pay more attention to his wives than to him/her." This brings us to the issue of child neglect. You claim that Type One polygamy will result in child neglect. However, child neglect is not limited to Type One polygamous marriages. Children from all familial backgrounds are capable of being neglected/abused. Read the case of "Genie." Her story inspired a film, The Mockingbird Don't Sing (2001). Child neglect is not limited to Type One polygamous marriages.

Polygamy has led to rejection and sometimes domestic violence between another because of jealousy. I feel that there should be a marriage between 2 beings, whether it's of the same gender or of two different genders. At least then, the couple can focus on each other, and not find themselves to be jealous about others unless it were to be an affair, but otherwise, the two can live happily together. They will find affection between themselves and not with others. Although, honestly, con's side of the debate brings a good argument.

I did not argue to bring inequality into people who support polygamy. I just feel it is not the healthiest type of relationship. Overall, there is a higher chance of domestic violence, rejection and an unhealthy environment for their child(ren).

I regrettably bet you will have drug addiction and homelessness in your midlife if you engage in polygamist ideals, not to mention you will never help poor people significantly enough to actually admit U Helped, and no a dinner is not help (you can go days without eating. it doesnt help life crises like loneliness and war.).

if I can come up with four reasons, then you should come up with 4, and then disprove mine. and I will disprove yours.

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1.)
Jealousy invokes all rape and murder by those of whom do not support the fall of society and it's morals. It would further pervert people with NO wives into disgraceful misconduct. Unavoidably, Polygamy would inhibit a class of people who Hate everyone out of Jealous.
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2.)
The time spent by these families would be a siphon on society. Their contributions would be far exceeded by how much they take from society. They would be a cancer. In all forms: even the destruction of pre-existing marriages
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3.)
enmity: Mormonism dictates you can have one wife so that you do not create enmity (book of Mormon.). Current wifes would need to deal with their husbands having other women receive their appreciation. Most men are lazy or incompetent in some way or another, already creating grief in relationships, increasing the party size will create further discord and lack of appreciation. NOtice most men are already frowned upon, and women complain a lot, this will only become worse.
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4.)
In regards to social structure. we will have more poor (married and poor), more lonely, more outcasts, more drug addicts (in and out of marriage), more divorces, more divorce amongst parents, more politic injustice.

Factually the world is already struggling with the term 'Rape'. Rape being unappreciated conduct, or pain inflicting conduct during sex: sex can turn into rape if he is inconsiderate or rash. People do not accept that. There would be more rape, and wifes hating each other.

I am pro Polygamy. I am. BUt NNOOO, it should not be legal.
You must remove the idiots before you give them laws which permit idioucy to prosper uncontested. You would only be enabling the asssholes of the world. If youw ant 3 sums, I recomend u burn in hell for your incompetant brain functions.